Joe Wilson’s review published on Letterboxd:
After Dr. No, From Russia with Love, and Goldfinger, Thunderball seemed kind of boring, to be honest. That's not to say there aren't memorable moments; the underwater stuff especially was quite an achievement and I was engaged on a filmmaking fan level; unfortunately, it was hard to tell who was who, what was going on, and why I should care.
Bond seemed to care less in this one as well, compared to the other ones. I don't know why, but even though SPECTRE was threatening to detonate an atomic bomb in Miami, Thunderball's stakes felt the lowest out of any of the series so far. The stakes did not seem to matter as much to Bond, and consequently to me.
Thunderball is far from a bad film, but doesn't follow up the promise of the first three Bond films. I understand that going forward Connery's record is spotty at best; very sad, because so far I do think that the OG is my favorite Bond, rapey moments aside (there's one in this movie too, though not as egregious as Goldfinger).